With apologies for the delays (I was on a business trip in the U.S.) here are some notes on P3Dv4.5 and its compatibility with my planes.
First thing: at the moment I am writing, VRS has not yet updated Tacpack to support P3Dv4.5. Tacpack is built in such a way that it needs to be updated each time a new version of P3D is released so it is not a surprise. However, some of my planes rely heavily on it (especially the F-35 and the Typhoon) - so you may want to wait until Tacpack is updated before switching to P3Dv4.5.
That being said, on my system P3Dv4.5 works fine with no significant issues. Actually I am under the impression that frame rates and texture resolution are improved (keeping in mind that I typically fly over large photoreal sceneries such as the ones from Blue Sky).
The only minor problem I am having is a strange and subtle "blurry" effect in VR which is difficult to describe (and may be due to my system settings)… will report on that after further testing.
As I supposed, there are no buig differences in the code or compatibility in my planes - so they all work as expected. In detail:
F-35 Lightning II
Everything seems to work fine including STOVL, custom sound and fuel system. Until Tacpack is updated, DAS, TFLIR, A/A radar, loadout configurator and weapon system functionalities will not work.
SIAI Marchetti S-211 / Aermacchi M-345
E-2 Hawkeye / C-2 Greyhound
All freeware aircrafts will work on P3Dv4.5 to the same extent as they did in P3V4.4.